Storage Considerations for VMware® vCloud™ Director

Storage Considerations for VMware® vCloud™ Director VMware vCloud Director Version 1.0 Tech n ical Wh iTe PaPe R Storage Considerations for VMware vCloud Director Introduction VMware® vCloud™ Director is a new solution that addresses the challenge of rapidly provisioning resources in VMware vSphere™ 4.1 (“vSphere”) to support multitenancy environments. It adds a layer of automation, security and simplicity built for both internal private networks, for large enterprises, as well as large cloud deployments, for service providers. With this release VMware has created a new administrator role within the virtualized datacenter. The role of a vCloud Director administrator as well as a cloud consumer means that some new layers of management will require understanding of new terminology and concepts. This paper has been written to explain the relationships of both the storage-resource and storage-management functions introduced by vCloud Director, as well as to provide an overview of the steps taken to provision storage in vCloud Director and to share some best practices and consideration for deployment. The intended audience for this paper is storage-focused technical personnel who have a strong understanding of vSphere 4.1. This paper assumes the reader has a solid command of the VMware concepts and terminology. VMware vCloud Director Overview VMware vCloud Director is a software solution that enables enterprises to build secure, multitenant private clouds by pooling infrastructure resources into virtual datacenters and exposing them to users through Web-based portals and programmatic interfaces as fully automated, catalog-based services. By building secure and cost-effective private clouds with VMware vSphere and VMware vCloud Director, internal IT organizations can act as true service providers for the businesses they support, driving innovation and agility while increasing IT eficiency and enhancing security. This solution provides a pragmatic path to cloud computing by giving customers the power to leverage existing investments and the flexibility to extend capacity between clouds. The intent of vCloud Director is to help move the datacenters of the virtualized world closer to the true value of cloud computing. vCloud Director provides automation and reduced management intradependencies of compute, network and storage. The specific focus of this paper is on storage. Virtualized compute, network and storage resources created in a vSphere environment can now be grouped into logical virtual data centers (VDC) that can be safely shared by many consumers. VMware vCloud Director Environment vCenter vCloud Management cluster 3 x Dell PE 2950 (2 cpu, 32 GB RAM per server) Private cloud cluster 4 x HP DL 380 G6 (2 cpu, 24 GB RAM per server) RP 01 RP 02 RP 03 VMware vCloud Director vCenter Server Chargeback vShield Manager Directory services, DNS, DHCP Primary Directory services, DNS, DHCP Secondary Oracle database SQL FC Storage iSCSI Storage NFS Storage Server database Figure 1. VMware vCloud Architecture Overview. T ec h n i c a l W h iT e Pa P e R / 2 Storage Considerations for VMware vCloud Director VMware vCloud Director Storage Overview In the vCloud Director environment, the provider exposes a set of virtualized compute, storage and networking resources to be consumed by users in the cloud. The pooling of pure virtual resources will be defined and managed through vCloud Director by the administrator in a way that offers both elasticity and scalability. From the user (consumer) perspective the storage resources appear as a limitless pool of storage that has a uniform performance characteristic and cost. The goal of vCloud Director is to provide consumers with limitless storage capacity so that they can consume as much as possible if they are willing to pay for it. VMware vCloud Director Terminology A Provider VDC is a combination of compute and storage resources. One can take compute and storage resources with specific characteristics, such as cost and performance, and combine them and create a Provider VDC. When this is done, one can logically tier pools of compute and storage resources into multiple-service offerings, each implemented by one or more Provider VDCs. Each Provider VDC will have an SLA and cost associated with it and is intended to be a shared resource. VMware vCloud Director allows you to create Organizations to separate groups of users from each other and apply different policy controls. Each Organization can contain different groups of users that has its own set of resources and policies. VMware vCloud Director creates a separate Web-based access point (URL) for each Organization where users of that Organization log in. Inside Organizations, one can create users and groups. Users can be authenticated in three different ways: 1. Locally against the VMware vCloud Director database 2. Systemwide VMware vCloud Director active directory or LDAP server 3. Organization-specific active directory or LDAP server An Organization VDC is a resource container that contains compute and storage resources and has a specific SLA and cost associated depending on which Provider VDC it is created from. Organization VDCs are created so that Organizations can use resources from Provider VDCs. An Organization VDC can grow to be as large as the size of a Provider VDC. An Organization can use resources through multiple Organization VDCs created from multiple Provider VDCs. There are three ways of consuming resources from a provider VDC. 1. Pay Per Virtual Machine (VM) a. There is no upfront resource allocation. b. Organization VDC resources are allocated only as users create vApps. c. One can set limits to cap usage. d. One can guarantee a percentage of the resources being used to provide overcommitment of compute and memory across your cloud. 2. Reservation Pool a. An Organization VDC is allocated a “container” set of resources. b. Organizations can use advanced vSphere resource-management controls such as Shares and Reservations to manage overcommitment of their resources between their workloads. Some more sophisticated aspects of resource management are owned by the cloud tenant and not the cloud operator. T ec h n i c a l W h iT e Pa P e R / 3 Storage Considerations for VMware vCloud Director 3. Allocation Pool a. An Organization VDC is allocated a “container” set of resources. b. Organizations have very simple models of resources, and advanced resource-management controls such as Shares and Reservations are managed by the cloud operator, thus enabling more coherent resource management across Organizations. Pooling of Storage Resources A Provider VDC is a resource pool of a cluster of VMware ESX® servers that access a shared storage resource. The Provider VDC can contain: 1) part of a datastore (shared by other Provider VDCs); 2) all of a datastore; or 3) multiple datastores. As storage is provisioned to Organization VDCs, the shared storage pool for the Provider VDC is seen as one pool of storage with no distinction of storage characteristics, protocol or other characteristics that differentiate it from being more than just one large address space. In the case of a Provider VDC that is comprised of more than one datastore, it is considered best practice that those datastores have equal performance capability, protocol and quality of service. If this is not the case, the performance of that Provider VDC storage pool will be impacted by the slower storage in the collective pool. Some VDCs might end up with faster storage than others. In order to gain the benefits of different storage tiers or protocols, one will need to define separate Provider VDCs where each Provider VDC would have storage of different protocols or differing quality-of-service storage. For example, one might provision a Provider VDC that is built on a datastore backed by 15K RPM FC disks with loads of cache in the disk for the highest disk performance tier, and a second Provider VDC that is built on a datastore backed by SATA drives and not a lot of cache in the array for a lower tier. It should be noted that when a Provider VDC has a datastore that is shared with another Provider VDC one may find the performance of one Provider VDC is causing performance impact on another Provider VDC. So, it is considered best practice to have a Provider VDC that has a dedicated datastore such that isolation of the storage reduces chances of introducing the existence of different quality-of-service storage resources in one Provider VDC. Org VDCs in FC PVDC FC PVDC FC Datastore FC LUN Org VDCs in iSCl PVDC iSCSl PVDC iSCSl Datastore iSCSl LUN Org VDCs in NFS PVDC NFS PVDC NFS Datastore NFS Device Figure 2. Logical Boundaries Separating Storage Types. T ec h n i c a l W h iT e Pa P e R / 4 Storage Considerations for VMware vCloud Director vCloud Director Storage Requirements Deployment of VMware vCloud Director requires storage for several elements of the overall architecture. The first use of storage is the storage needed to house the management cluster of vCloud Director. This will include the repository for information about the configuration, Organizations and allocations that are stored in an Oracle database. That storage requirement is called out in the configuration guide and evaluation guide. The second storage requirement is the vSphere storage objects that are presented to vCloud Director as datastores accessed by ESX servers in the vCloud Director configuration. This storage is managed by the vSphere administrator and is consumed by vCloud Director users pursuant to how the vCloud Director configuration is used at that higher level of abstraction. It is this third element of storage management on which the remainder of this paper will focus. It will explain how one configures, manages and monitors the storage made available through vSphere for consumption by users within the scope of the vCloud Director. As a basic installation, it is required that there be at least two vSphere datastores presented to vCloud Director of about 300GB or larger in size, preferably, datastores with different storage performance capabilities. An additional storage requirement for deployment of vCloud Director is the existence of a single NFS datastore to serve as a staging area for vApps to be uploaded to a Catalog. Assuming the management cluster of vCloud Director is installed as outlined in the installation guide and vSphere has been set up such that datastores are available to the vCloud Director configuration, we will now run through the steps making storage available to consumers of the vCloud Director environment. Steps for Configuring Storage in VMware vCloud Director The basic steps for provisioning storage for vCloud Director are as follows: • Create datastores within vSphere for use by vCloud Director. • Confirm that the datastores are visible in the vCloud Director console. • Create Provider VDCs by associating compute resource pool with shared storage. • Create Organizations. • Create Organization VDCs. • Deploy vApps and consume storage resources in Organization VDC. Typically the first step above is done by the vSphere administrator. Steps 2 through 5 are done by the vCloud Director administrator. And the last step is done by the cloud end-user community. Viewing the Datastores Within vCloud Director From within the vCloud Director console one can view the vSphere storage resources available for building Provider VDCs by selecting the “Datastore” icon from the Manage and Monitor tab. In the case of the example shown in Figure 3, there are three datastores available. The attributes of these datastores are reflected in the columns shown in Figure 3. T ec h n i c a l W h iT e Pa P e R / 5 ... - tailieumienphi.vn